From the time that the first settlers came to the Raritan Valley in 1688, they were considered as included in Middlesex County and depended upon the courts there for the administration of civil justice. County boundaries were surveyed and variously adjusted in 1709, 1741,1749, and 1790. Somerset County embraces a portion of the most fertile lands in New Jersey.

A brief inquiry into the origin of names will bring us to fair Somersetshire in Old England, the ancestral home of Henry VIII's brother-in-law, and so too, doubtless of the early settlers of Somerset County. Perhaps they found in these New Jersey foothills some suggestions of the mountains, moors, and fens that characterize old Somersetshire, the land of Lorna Doone and John Ridd, the West Wales of the romances of Arthur and his Round Table. In any case the county name records the memory of their old home for all time. So too, the townships of Bridgewater and Bedminster, and the town of High Bridge, once within the county limits, but later across the borders of Hunterdon County, are but names transplanted from old Somerset.